<template>
  <div class="upload-file">
    <el-upload multiple :action="uploadFileUrl" :before-upload="handleBeforeUpload" :file-list="fileList" :limit="limit"
      :on-error="handleUploadError" :on-exceed="handleExceed" :on-success="handleUploadSuccess" :show-file-list="false"
      :headers="headers" :accept="fileType.join(', ')" class="upload-file-uploader" ref="fileUpload">
      <!-- 上传按钮 -->
      <el-button type="primary">选取文件</el-button>
    </el-upload>
    <!-- 上传提示 -->
    <div class="el-upload__tip" v-if="showTip">
      请上传
      <template v-if="fileSize"> 大小不超过 <b>{{ fileSize }}MB</b> </template>
      <template v-if="fileType"> 格式为 <b>{{ fileType.join("/") }}</b> </template>
      的文件
    </div>
    <!-- 文件列表 -->
    <transition-group name="el-fade-in-linear" tag="ul">
      <li :key="file.uid" class="flex" v-for="(file, index) in fileList">
        <el-link type="primary" :underline="false" @click="viewImageRef.open(file.url)">{{ file.name }}</el-link>
        <el-button :underline="false" @click="handleDelete(index)" link type="danger" class="ml-2">删除</el-button>
      </li>
    </transition-group>
    <ViewImage ref="viewImageRef"/>
  </div>
</template>

<script setup>
import { getToken } from "@/utils/auth"

const props = defineProps({
  modelValue: { type: Array, default: () => ([]) },
  // 数量限制
  limit: {
    type: Number,
    default: 5,
  },
  // 大小限制(MB)
  fileSize: {
    type: Number,
    default: 5,
  },
  // 文件类型, 例如['png', 'jpg', 'jpeg']
  fileType: {
    type: Array,
    default: () => ["doc", "xls", "ppt", "txt", "pdf"],
  },
  // 是否显示提示
  isShowTip: {
    type: Boolean,
    default: true
  }
});

const { proxy } = getCurrentInstance();
const emit = defineEmits(['update:modelValue'])
const number = ref(0);
const uploadList = ref([]);
const baseUrl = import.meta.env.VITE_APP_BASE_API;
const uploadFileUrl = ref(import.meta.env.VITE_APP_BASE_API + 'v1/base/upload'); // 上传文件服务器地址
const headers = ref({ Authorization: "Bearer " + getToken() })
const viewImageRef = ref()
const showTip = computed(
  () => props.isShowTip && (props.fileType || props.fileSize)
)


const fileList = computed({
  get() {
    return props.modelValue.map(url => {
      const name = url.slice(url.lastIndexOf("/") + 1)
      return { name, url }
    })
  },
  set(val) {
    emit("update:modelValue", val.map(d => d.url))
  }
})

// 上传前校检格式和大小
function handleBeforeUpload(file) {
  // 校检文件类型
  if (props.fileType.length) {
    const fileName = file.name.split('.');
    const fileExt = fileName[fileName.length - 1];
    const isTypeOk = props.fileType.indexOf(fileExt) >= 0;
    if (!isTypeOk) {
      proxy.$modal.msgError(`文件格式不正确, 请上传${props.fileType.join("/")}格式文件!`);
      return false;
    }
  }
  // 校检文件大小
  if (props.fileSize) {
    const isLt = file.size / 1024 / 1024 < props.fileSize;
    if (!isLt) {
      proxy.$modal.msgError(`上传文件大小不能超过 ${props.fileSize} MB!`);
      return false;
    }
  }
  proxy.$modal.loading("正在上传文件，请稍候...");
  number.value++;
  return true;
}

// 文件个数超出
function handleExceed() {
  proxy.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`);
}

// 上传失败
function handleUploadError(err) {
  proxy.$modal.msgError("上传文件失败");
}

// 上传成功回调
function handleUploadSuccess(res, file) {
  const { file_preview } = res.data[0]
  if (res.code === 200) {
    if (props.limit === 1) {
      uploadList.value = [{ name: file_preview, url: file_preview }]
    } else {
      uploadList.value.push({ name: file_preview, url: file_preview })
    }
    uploadedSuccessfully();
  } else {
    number.value--;
    proxy.$modal.closeLoading();
    proxy.$modal.msgError(res.msg);
    proxy.$refs.fileUpload.handleRemove(file);
    uploadedSuccessfully();
  }
}

// 删除图片
function handleDelete(index) {
  fileList.value = fileList.value.filter((d, i) => i !== index)
}

// 上传结束处理
function uploadedSuccessfully() {
  if (number.value > 0 && uploadList.value.length === number.value) {
    fileList.value = props.limit === 1 ? uploadList.value : fileList.value.filter(f => f.url !== undefined).concat(uploadList.value);
    uploadList.value = [];
    number.value = 0;
    proxy.$modal.closeLoading();
  }
}

// 对象转成指定字符串分隔
function listToString(list, separator) {
  let strs = "";
  separator = separator || ",";
  for (let i in list) {
    if (list[i].url) {
      strs += list[i].url + separator;
    }
  }
  return strs != '' ? strs.substr(0, strs.length - 1) : '';
}
</script>
